The present invention relates generally to devices for reducing injury to pedestrians when struck by a vehicle, and more specifically to an apparatus and method for reducing the severity and likelihood of injury caused by impact between a pedestrian and a vehicle""s A-pillars.
It is an objective of current vehicle design to reduce the likelihood and/or severity of injury to pedestrians that may be struck by a vehicle. Most proposals to achieve this reduction have focused on increasing the energy absorbing characteristics of the bumper/grille area of the vehicle or the hood. Among the proposed devices are airbags mounted at various external locations on the vehicle and deployable hoods that are raised upward prior to the impact to provide additional crush space between the hood and objects in the engine compartment.
In vehicle/pedestrian collisions in which the pedestrian is thrown over or onto the vehicle hood, impact of the pedestrian with one of the vehicle""s A-pillars can be a significant source of injury. The A-pillars are the structural members of the vehicle body that extend upward and rearward from the rear of the fenders to the forward outboard corners of the roof, along either side of the windshield. The A-pillars must be quite strong to support the roof and the windshield during normal vehicle operation and during a rollover accident. As a result, the A-pillars must be quite rigid, and it is difficult to design the A-pillars to absorb a significant amount of impact energy when struck by a pedestrian.
The present invention provides a pedestrian protection apparatus for a motor vehicle having a hood, a windshield, and left and right A-pillars disposed adjacent left and right ends of the windshield respectively. The apparatus comprises left and right A-pillar covers having a retracted condition wherein they are adjacent the respective A-pillars, and movable to a deployed condition wherein the A-pillar covers are spaced forwardly from the respective A-pillars. An actuator system operates to move the A-pillar covers from the retracted condition to the deployed condition prior to a pedestrian impact with the A-pillar covers. In the deployed condition, the A-pillar covers are able to move rearwardly when struck by a pedestrian so as to absorb impact energy and thereby lessen the likelihood and/or severity of injury, as compared with the case where the pedestrian strikes a conventional, stationary A-pillar.
In a preferred embodiment of the invention, upper ends of the A-pillar covers attached to the respective A-pillars by hinges such that the A-pillar covers rotate about their upper ends to move from the retracted condition to the deployed condition. This results in the lower ends of the A-pillar covers being able to travel a longer distance rearward, and thus absorb a greater amount of impact energy. This is advantageous because the probability of pedestrian impact with the A-pillars is greater adjacent the lower ends of the A-pillars, closer to the hood.
Also in a preferred embodiment, the actuator system comprises one or more pyrotechnic devices for generating gas pressure to drive a mechanical linkage connected to the A-pillar covers when the pyrotechnic is activated. The actuator system may comprise a contact sensor for detecting a pedestrian impact with a front section of the vehicle, and/or a remote sensor for detecting an impending pedestrian impact with a front section of the vehicle.
According to a feature of the invention, the A-pillar covers when in the deployed condition are deformable in response to a pedestrian impact, the deformation serving to absorb impact energy.
According to another feature of the invention, at least one damper is operatively connected with the A-pillar covers to provide controlled resistance to movement of the A-pillar covers from the deployed condition toward the retracted condition in order to absorb impact energy. The damper may be a separate component from the actuator mechanism, or may be integrated. with the actuator mechanism.
According to another feature of the invention, the hood of the vehicle may be provided with a hood deployment mechanism operative to move the hood to a raised position substantially simultaneously with movement of the A-pillar covers to the deployed condition. Raising the hood increases the amount of space between the hood and rigid objects in the engine compartment, such as the engine, battery, shock absorber mounts, etc. This additional xe2x80x9ccrush spacexe2x80x9d allows the hood to yield under impact of the pedestrian by an amount sufficient to absorb a significant amount of the impact energy, further deceasing the likelihood and/or severity of injury to the pedestrian.
According to another feature of the invention, the windshield moves along with the A-pillar covers to the deployed condition so that it is able to yield rearwardly along with A-pillar covers in order to absorb the impact energy of a pedestrian striking the windshield.
The invention also provides a method for lessening the degree of injury suffered by a pedestrian when struck by a motor vehicle, the method comprising the steps of predicting an impact of the pedestrian with the vehicle and moving a left A-pillar cover and a right A-pillar cover from a retracted condition to a deployed condition wherein the A-pillar covers are spaced forwardly from the respective A-pillars in order to absorb impact energy.